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h264_refs.c
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1 /*
2  * H.26L/H.264/AVC/JVT/14496-10/... reference picture handling
3  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * H.264 / AVC / MPEG4 part10 reference picture handling.
25  * @author Michael Niedermayer <michaelni@gmx.at>
26  */
27 
28 #include "libavutil/avassert.h"
29 #include "internal.h"
30 #include "avcodec.h"
31 #include "h264.h"
32 #include "golomb.h"
33 
34 #include <assert.h>
35 
36 #define COPY_PICTURE(dst, src) \
37 do {\
38  *(dst) = *(src);\
39  (dst)->f.extended_data = (dst)->f.data;\
40  (dst)->tf.f = &(dst)->f;\
41 } while (0)
42 
43 
44 static void pic_as_field(Picture *pic, const int parity){
45  int i;
46  for (i = 0; i < 4; ++i) {
47  if (parity == PICT_BOTTOM_FIELD)
48  pic->f.data[i] += pic->f.linesize[i];
49  pic->reference = parity;
50  pic->f.linesize[i] *= 2;
51  }
52  pic->poc= pic->field_poc[parity == PICT_BOTTOM_FIELD];
53 }
54 
55 static int split_field_copy(Picture *dest, Picture *src, int parity, int id_add)
56 {
57  int match = !!(src->reference & parity);
58 
59  if (match) {
60  COPY_PICTURE(dest, src);
61  if (parity != PICT_FRAME) {
62  pic_as_field(dest, parity);
63  dest->pic_id *= 2;
64  dest->pic_id += id_add;
65  }
66  }
67 
68  return match;
69 }
70 
71 static int build_def_list(Picture *def, Picture **in, int len, int is_long, int sel)
72 {
73  int i[2] = { 0 };
74  int index = 0;
75 
76  while (i[0] < len || i[1] < len) {
77  while (i[0] < len && !(in[i[0]] && (in[i[0]]->reference & sel)))
78  i[0]++;
79  while (i[1] < len && !(in[i[1]] && (in[i[1]]->reference & (sel ^ 3))))
80  i[1]++;
81  if (i[0] < len) {
82  in[i[0]]->pic_id = is_long ? i[0] : in[i[0]]->frame_num;
83  split_field_copy(&def[index++], in[i[0]++], sel, 1);
84  }
85  if (i[1] < len) {
86  in[i[1]]->pic_id = is_long ? i[1] : in[i[1]]->frame_num;
87  split_field_copy(&def[index++], in[i[1]++], sel ^ 3, 0);
88  }
89  }
90 
91  return index;
92 }
93 
94 static int add_sorted(Picture **sorted, Picture **src, int len, int limit, int dir)
95 {
96  int i, best_poc;
97  int out_i = 0;
98 
99  for (;;) {
100  best_poc = dir ? INT_MIN : INT_MAX;
101 
102  for (i = 0; i < len; i++) {
103  const int poc = src[i]->poc;
104  if (((poc > limit) ^ dir) && ((poc < best_poc) ^ dir)) {
105  best_poc = poc;
106  sorted[out_i] = src[i];
107  }
108  }
109  if (best_poc == (dir ? INT_MIN : INT_MAX))
110  break;
111  limit = sorted[out_i++]->poc - dir;
112  }
113  return out_i;
114 }
115 
117 {
118  int i, len;
119 
120  if (h->slice_type_nos == AV_PICTURE_TYPE_B) {
121  Picture *sorted[32];
122  int cur_poc, list;
123  int lens[2];
124 
125  if (FIELD_PICTURE(h))
127  else
128  cur_poc = h->cur_pic_ptr->poc;
129 
130  for (list = 0; list < 2; list++) {
131  len = add_sorted(sorted, h->short_ref, h->short_ref_count, cur_poc, 1 ^ list);
132  len += add_sorted(sorted + len, h->short_ref, h->short_ref_count, cur_poc, 0 ^ list);
133  av_assert0(len <= 32);
134  len = build_def_list(h->default_ref_list[list], sorted, len, 0, h->picture_structure);
135  len += build_def_list(h->default_ref_list[list] + len, h->long_ref, 16, 1, h->picture_structure);
136  av_assert0(len <= 32);
137 
138  if (len < h->ref_count[list])
139  memset(&h->default_ref_list[list][len], 0, sizeof(Picture) * (h->ref_count[list] - len));
140  lens[list] = len;
141  }
142 
143  if (lens[0] == lens[1] && lens[1] > 1) {
144  for (i = 0; h->default_ref_list[0][i].f.data[0] == h->default_ref_list[1][i].f.data[0] && i < lens[0]; i++);
145  if (i == lens[0]) {
146  Picture tmp;
147  COPY_PICTURE(&tmp, &h->default_ref_list[1][0]);
148  COPY_PICTURE(&h->default_ref_list[1][0], &h->default_ref_list[1][1]);
149  COPY_PICTURE(&h->default_ref_list[1][1], &tmp);
150  }
151  }
152  } else {
154  len += build_def_list(h->default_ref_list[0] + len, h-> long_ref, 16, 1, h->picture_structure);
155  av_assert0(len <= 32);
156  if (len < h->ref_count[0])
157  memset(&h->default_ref_list[0][len], 0, sizeof(Picture) * (h->ref_count[0] - len));
158  }
159 #ifdef TRACE
160  for (i = 0; i < h->ref_count[0]; i++) {
161  tprintf(h->avctx, "List0: %s fn:%d 0x%p\n",
162  (h->default_ref_list[0][i].long_ref ? "LT" : "ST"),
163  h->default_ref_list[0][i].pic_id,
164  h->default_ref_list[0][i].f.data[0]);
165  }
166  if (h->slice_type_nos == AV_PICTURE_TYPE_B) {
167  for (i = 0; i < h->ref_count[1]; i++) {
168  tprintf(h->avctx, "List1: %s fn:%d 0x%p\n",
169  (h->default_ref_list[1][i].long_ref ? "LT" : "ST"),
170  h->default_ref_list[1][i].pic_id,
171  h->default_ref_list[1][i].f.data[0]);
172  }
173  }
174 #endif
175  return 0;
176 }
177 
178 static void print_short_term(H264Context *h);
179 static void print_long_term(H264Context *h);
180 
181 /**
182  * Extract structure information about the picture described by pic_num in
183  * the current decoding context (frame or field). Note that pic_num is
184  * picture number without wrapping (so, 0<=pic_num<max_pic_num).
185  * @param pic_num picture number for which to extract structure information
186  * @param structure one of PICT_XXX describing structure of picture
187  * with pic_num
188  * @return frame number (short term) or long term index of picture
189  * described by pic_num
190  */
191 static int pic_num_extract(H264Context *h, int pic_num, int *structure)
192 {
193  *structure = h->picture_structure;
194  if (FIELD_PICTURE(h)) {
195  if (!(pic_num & 1))
196  /* opposite field */
197  *structure ^= PICT_FRAME;
198  pic_num >>= 1;
199  }
200 
201  return pic_num;
202 }
203 
205 {
206  int list, index, pic_structure, i;
207 
208  print_short_term(h);
209  print_long_term(h);
210 
211  for (list = 0; list < h->list_count; list++) {
212  for (i = 0; i < h->ref_count[list]; i++)
213  COPY_PICTURE(&h->ref_list[list][i], &h->default_ref_list[list][i]);
214 
215  if (get_bits1(&h->gb)) {
216  int pred = h->curr_pic_num;
217 
218  for (index = 0; ; index++) {
219  unsigned int reordering_of_pic_nums_idc = get_ue_golomb_31(&h->gb);
220  unsigned int pic_id;
221  int i;
222  Picture *ref = NULL;
223 
224  if (reordering_of_pic_nums_idc == 3)
225  break;
226 
227  if (index >= h->ref_count[list]) {
228  av_log(h->avctx, AV_LOG_ERROR, "reference count overflow\n");
229  return -1;
230  }
231 
232  if (reordering_of_pic_nums_idc < 3) {
233  if (reordering_of_pic_nums_idc < 2) {
234  const unsigned int abs_diff_pic_num = get_ue_golomb(&h->gb) + 1;
235  int frame_num;
236 
237  if (abs_diff_pic_num > h->max_pic_num) {
238  av_log(h->avctx, AV_LOG_ERROR, "abs_diff_pic_num overflow\n");
239  return -1;
240  }
241 
242  if (reordering_of_pic_nums_idc == 0)
243  pred -= abs_diff_pic_num;
244  else
245  pred += abs_diff_pic_num;
246  pred &= h->max_pic_num - 1;
247 
248  frame_num = pic_num_extract(h, pred, &pic_structure);
249 
250  for (i = h->short_ref_count - 1; i >= 0; i--) {
251  ref = h->short_ref[i];
252  assert(ref->reference);
253  assert(!ref->long_ref);
254  if (ref->frame_num == frame_num &&
255  (ref->reference & pic_structure))
256  break;
257  }
258  if (i >= 0)
259  ref->pic_id = pred;
260  } else {
261  int long_idx;
262  pic_id = get_ue_golomb(&h->gb); //long_term_pic_idx
263 
264  long_idx = pic_num_extract(h, pic_id, &pic_structure);
265 
266  if (long_idx > 31) {
267  av_log(h->avctx, AV_LOG_ERROR, "long_term_pic_idx overflow\n");
268  return -1;
269  }
270  ref = h->long_ref[long_idx];
271  assert(!(ref && !ref->reference));
272  if (ref && (ref->reference & pic_structure)) {
273  ref->pic_id = pic_id;
274  assert(ref->long_ref);
275  i = 0;
276  } else {
277  i = -1;
278  }
279  }
280 
281  if (i < 0) {
282  av_log(h->avctx, AV_LOG_ERROR, "reference picture missing during reorder\n");
283  memset(&h->ref_list[list][index], 0, sizeof(Picture)); //FIXME
284  } else {
285  for (i = index; i + 1 < h->ref_count[list]; i++) {
286  if (ref->long_ref == h->ref_list[list][i].long_ref &&
287  ref->pic_id == h->ref_list[list][i].pic_id)
288  break;
289  }
290  for (; i > index; i--) {
291  COPY_PICTURE(&h->ref_list[list][i], &h->ref_list[list][i - 1]);
292  }
293  COPY_PICTURE(&h->ref_list[list][index], ref);
294  if (FIELD_PICTURE(h)) {
295  pic_as_field(&h->ref_list[list][index], pic_structure);
296  }
297  }
298  } else {
299  av_log(h->avctx, AV_LOG_ERROR, "illegal reordering_of_pic_nums_idc\n");
300  return -1;
301  }
302  }
303  }
304  }
305  for (list = 0; list < h->list_count; list++) {
306  for (index = 0; index < h->ref_count[list]; index++) {
307  if ( !h->ref_list[list][index].f.data[0]
308  || (!FIELD_PICTURE(h) && (h->ref_list[list][index].reference&3) != 3)) {
309  int i;
310  av_log(h->avctx, AV_LOG_ERROR, "Missing reference picture, default is %d\n", h->default_ref_list[list][0].poc);
311  for (i = 0; i < FF_ARRAY_ELEMS(h->last_pocs); i++)
312  h->last_pocs[i] = INT_MIN;
313  if (h->default_ref_list[list][0].f.data[0]
314  && !(!FIELD_PICTURE(h) && (h->default_ref_list[list][0].reference&3) != 3))
315  COPY_PICTURE(&h->ref_list[list][index], &h->default_ref_list[list][0]);
316  else
317  return -1;
318  }
319  av_assert0(av_buffer_get_ref_count(h->ref_list[list][index].f.buf[0]) > 0);
320  }
321  }
322 
323  return 0;
324 }
325 
327 {
328  int list, i, j;
329  for (list = 0; list < h->list_count; list++) {
330  for (i = 0; i < h->ref_count[list]; i++) {
331  Picture *frame = &h->ref_list[list][i];
332  Picture *field = &h->ref_list[list][16 + 2 * i];
333  COPY_PICTURE(field, frame);
334  for (j = 0; j < 3; j++)
335  field[0].f.linesize[j] <<= 1;
336  field[0].reference = PICT_TOP_FIELD;
337  field[0].poc = field[0].field_poc[0];
338  COPY_PICTURE(field + 1, field);
339  for (j = 0; j < 3; j++)
340  field[1].f.data[j] += frame->f.linesize[j];
341  field[1].reference = PICT_BOTTOM_FIELD;
342  field[1].poc = field[1].field_poc[1];
343 
344  h->luma_weight[16 + 2 * i][list][0] = h->luma_weight[16 + 2 * i + 1][list][0] = h->luma_weight[i][list][0];
345  h->luma_weight[16 + 2 * i][list][1] = h->luma_weight[16 + 2 * i + 1][list][1] = h->luma_weight[i][list][1];
346  for (j = 0; j < 2; j++) {
347  h->chroma_weight[16 + 2 * i][list][j][0] = h->chroma_weight[16 + 2 * i + 1][list][j][0] = h->chroma_weight[i][list][j][0];
348  h->chroma_weight[16 + 2 * i][list][j][1] = h->chroma_weight[16 + 2 * i + 1][list][j][1] = h->chroma_weight[i][list][j][1];
349  }
350  }
351  }
352 }
353 
354 /**
355  * Mark a picture as no longer needed for reference. The refmask
356  * argument allows unreferencing of individual fields or the whole frame.
357  * If the picture becomes entirely unreferenced, but is being held for
358  * display purposes, it is marked as such.
359  * @param refmask mask of fields to unreference; the mask is bitwise
360  * anded with the reference marking of pic
361  * @return non-zero if pic becomes entirely unreferenced (except possibly
362  * for display purposes) zero if one of the fields remains in
363  * reference
364  */
365 static inline int unreference_pic(H264Context *h, Picture *pic, int refmask)
366 {
367  int i;
368  if (pic->reference &= refmask) {
369  return 0;
370  } else {
371  for(i = 0; h->delayed_pic[i]; i++)
372  if(pic == h->delayed_pic[i]){
373  pic->reference = DELAYED_PIC_REF;
374  break;
375  }
376  return 1;
377  }
378 }
379 
380 /**
381  * Find a Picture in the short term reference list by frame number.
382  * @param frame_num frame number to search for
383  * @param idx the index into h->short_ref where returned picture is found
384  * undefined if no picture found.
385  * @return pointer to the found picture, or NULL if no pic with the provided
386  * frame number is found
387  */
388 static Picture *find_short(H264Context *h, int frame_num, int *idx)
389 {
390  int i;
391 
392  for (i = 0; i < h->short_ref_count; i++) {
393  Picture *pic = h->short_ref[i];
394  if (h->avctx->debug & FF_DEBUG_MMCO)
395  av_log(h->avctx, AV_LOG_DEBUG, "%d %d %p\n", i, pic->frame_num, pic);
396  if (pic->frame_num == frame_num) {
397  *idx = i;
398  return pic;
399  }
400  }
401  return NULL;
402 }
403 
404 /**
405  * Remove a picture from the short term reference list by its index in
406  * that list. This does no checking on the provided index; it is assumed
407  * to be valid. Other list entries are shifted down.
408  * @param i index into h->short_ref of picture to remove.
409  */
410 static void remove_short_at_index(H264Context *h, int i)
411 {
412  assert(i >= 0 && i < h->short_ref_count);
413  h->short_ref[i] = NULL;
414  if (--h->short_ref_count)
415  memmove(&h->short_ref[i], &h->short_ref[i + 1],
416  (h->short_ref_count - i) * sizeof(Picture*));
417 }
418 
419 /**
420  *
421  * @return the removed picture or NULL if an error occurs
422  */
423 static Picture *remove_short(H264Context *h, int frame_num, int ref_mask)
424 {
425  Picture *pic;
426  int i;
427 
428  if (h->avctx->debug & FF_DEBUG_MMCO)
429  av_log(h->avctx, AV_LOG_DEBUG, "remove short %d count %d\n", frame_num, h->short_ref_count);
430 
431  pic = find_short(h, frame_num, &i);
432  if (pic) {
433  if (unreference_pic(h, pic, ref_mask))
434  remove_short_at_index(h, i);
435  }
436 
437  return pic;
438 }
439 
440 /**
441  * Remove a picture from the long term reference list by its index in
442  * that list.
443  * @return the removed picture or NULL if an error occurs
444  */
445 static Picture *remove_long(H264Context *h, int i, int ref_mask)
446 {
447  Picture *pic;
448 
449  pic = h->long_ref[i];
450  if (pic) {
451  if (unreference_pic(h, pic, ref_mask)) {
452  assert(h->long_ref[i]->long_ref == 1);
453  h->long_ref[i]->long_ref = 0;
454  h->long_ref[i] = NULL;
455  h->long_ref_count--;
456  }
457  }
458 
459  return pic;
460 }
461 
463 {
464  int i;
465 
466  for (i = 0; i < 16; i++) {
467  remove_long(h, i, 0);
468  }
469  assert(h->long_ref_count == 0);
470 
471  for (i = 0; i < h->short_ref_count; i++) {
472  unreference_pic(h, h->short_ref[i], 0);
473  h->short_ref[i] = NULL;
474  }
475  h->short_ref_count = 0;
476 
477  memset(h->default_ref_list, 0, sizeof(h->default_ref_list));
478  memset(h->ref_list, 0, sizeof(h->ref_list));
479 }
480 
481 /**
482  * print short term list
483  */
485 {
486  uint32_t i;
487  if (h->avctx->debug & FF_DEBUG_MMCO) {
488  av_log(h->avctx, AV_LOG_DEBUG, "short term list:\n");
489  for (i = 0; i < h->short_ref_count; i++) {
490  Picture *pic = h->short_ref[i];
491  av_log(h->avctx, AV_LOG_DEBUG, "%d fn:%d poc:%d %p\n",
492  i, pic->frame_num, pic->poc, pic->f.data[0]);
493  }
494  }
495 }
496 
497 /**
498  * print long term list
499  */
501 {
502  uint32_t i;
503  if (h->avctx->debug & FF_DEBUG_MMCO) {
504  av_log(h->avctx, AV_LOG_DEBUG, "long term list:\n");
505  for (i = 0; i < 16; i++) {
506  Picture *pic = h->long_ref[i];
507  if (pic) {
508  av_log(h->avctx, AV_LOG_DEBUG, "%d fn:%d poc:%d %p\n",
509  i, pic->frame_num, pic->poc, pic->f.data[0]);
510  }
511  }
512  }
513 }
514 
515 static int check_opcodes(MMCO *mmco1, MMCO *mmco2, int n_mmcos)
516 {
517  int i;
518 
519  for (i = 0; i < n_mmcos; i++) {
520  if (mmco1[i].opcode != mmco2[i].opcode) {
521  av_log(NULL, AV_LOG_ERROR, "MMCO opcode [%d, %d] at %d mismatches between slices\n",
522  mmco1[i].opcode, mmco2[i].opcode, i);
523  return -1;
524  }
525  }
526 
527  return 0;
528 }
529 
531 {
532  MMCO mmco_temp[MAX_MMCO_COUNT], *mmco = first_slice ? h->mmco : mmco_temp;
533  int mmco_index = 0, i;
534 
535  if (h->short_ref_count &&
537  !(FIELD_PICTURE(h) && !h->first_field && h->cur_pic_ptr->reference)) {
538  mmco[0].opcode = MMCO_SHORT2UNUSED;
539  mmco[0].short_pic_num = h->short_ref[h->short_ref_count - 1]->frame_num;
540  mmco_index = 1;
541  if (FIELD_PICTURE(h)) {
542  mmco[0].short_pic_num *= 2;
543  mmco[1].opcode = MMCO_SHORT2UNUSED;
544  mmco[1].short_pic_num = mmco[0].short_pic_num + 1;
545  mmco_index = 2;
546  }
547  }
548 
549  if (first_slice) {
550  h->mmco_index = mmco_index;
551  } else if (!first_slice && mmco_index >= 0 &&
552  (mmco_index != h->mmco_index ||
553  (i = check_opcodes(h->mmco, mmco_temp, mmco_index)))) {
555  "Inconsistent MMCO state between slices [%d, %d]\n",
556  mmco_index, h->mmco_index);
557  return AVERROR_INVALIDDATA;
558  }
559  return 0;
560 }
561 
562 int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count)
563 {
564  int i, av_uninit(j);
565  int pps_count;
566  int current_ref_assigned = 0, err = 0;
567  Picture *av_uninit(pic);
568 
569  if ((h->avctx->debug & FF_DEBUG_MMCO) && mmco_count == 0)
570  av_log(h->avctx, AV_LOG_DEBUG, "no mmco here\n");
571 
572  for (i = 0; i < mmco_count; i++) {
573  int av_uninit(structure), av_uninit(frame_num);
574  if (h->avctx->debug & FF_DEBUG_MMCO)
575  av_log(h->avctx, AV_LOG_DEBUG, "mmco:%d %d %d\n", h->mmco[i].opcode,
576  h->mmco[i].short_pic_num, h->mmco[i].long_arg);
577 
578  if (mmco[i].opcode == MMCO_SHORT2UNUSED ||
579  mmco[i].opcode == MMCO_SHORT2LONG) {
580  frame_num = pic_num_extract(h, mmco[i].short_pic_num, &structure);
581  pic = find_short(h, frame_num, &j);
582  if (!pic) {
583  if (mmco[i].opcode != MMCO_SHORT2LONG ||
584  !h->long_ref[mmco[i].long_arg] ||
585  h->long_ref[mmco[i].long_arg]->frame_num != frame_num) {
586  av_log(h->avctx, h->short_ref_count ? AV_LOG_ERROR : AV_LOG_DEBUG, "mmco: unref short failure\n");
587  err = AVERROR_INVALIDDATA;
588  }
589  continue;
590  }
591  }
592 
593  switch (mmco[i].opcode) {
594  case MMCO_SHORT2UNUSED:
595  if (h->avctx->debug & FF_DEBUG_MMCO)
596  av_log(h->avctx, AV_LOG_DEBUG, "mmco: unref short %d count %d\n",
598  remove_short(h, frame_num, structure ^ PICT_FRAME);
599  break;
600  case MMCO_SHORT2LONG:
601  if (h->long_ref[mmco[i].long_arg] != pic)
602  remove_long(h, mmco[i].long_arg, 0);
603 
604  remove_short_at_index(h, j);
605  h->long_ref[ mmco[i].long_arg ] = pic;
606  if (h->long_ref[mmco[i].long_arg]) {
607  h->long_ref[mmco[i].long_arg]->long_ref = 1;
608  h->long_ref_count++;
609  }
610  break;
611  case MMCO_LONG2UNUSED:
612  j = pic_num_extract(h, mmco[i].long_arg, &structure);
613  pic = h->long_ref[j];
614  if (pic) {
615  remove_long(h, j, structure ^ PICT_FRAME);
616  } else if (h->avctx->debug & FF_DEBUG_MMCO)
617  av_log(h->avctx, AV_LOG_DEBUG, "mmco: unref long failure\n");
618  break;
619  case MMCO_LONG:
620  // Comment below left from previous code as it is an interresting note.
621  /* First field in pair is in short term list or
622  * at a different long term index.
623  * This is not allowed; see 7.4.3.3, notes 2 and 3.
624  * Report the problem and keep the pair where it is,
625  * and mark this field valid.
626  */
627 
628  if (h->long_ref[mmco[i].long_arg] != h->cur_pic_ptr) {
629  if (h->cur_pic_ptr->long_ref) {
630  for(j=0; j<16; j++) {
631  if(h->long_ref[j] == h->cur_pic_ptr) {
632  remove_long(h, j, 0);
633  av_log(h->avctx, AV_LOG_ERROR, "mmco: cannot assign current picture to 2 long term references\n");
634  }
635  }
636  }
638  remove_long(h, mmco[i].long_arg, 0);
639  if (remove_short(h, h->cur_pic_ptr->frame_num, 0)) {
640  av_log(h->avctx, AV_LOG_ERROR, "mmco: cannot assign current picture to short and long at the same time\n");
641  }
642 
643  h->long_ref[mmco[i].long_arg] = h->cur_pic_ptr;
644  h->long_ref[mmco[i].long_arg]->long_ref = 1;
645  h->long_ref_count++;
646  }
647 
649  current_ref_assigned = 1;
650  break;
651  case MMCO_SET_MAX_LONG:
652  assert(mmco[i].long_arg <= 16);
653  // just remove the long term which index is greater than new max
654  for (j = mmco[i].long_arg; j < 16; j++) {
655  remove_long(h, j, 0);
656  }
657  break;
658  case MMCO_RESET:
659  while (h->short_ref_count) {
660  remove_short(h, h->short_ref[0]->frame_num, 0);
661  }
662  for (j = 0; j < 16; j++) {
663  remove_long(h, j, 0);
664  }
665  h->frame_num = h->cur_pic_ptr->frame_num = 0;
666  h->mmco_reset = 1;
667  h->cur_pic_ptr->mmco_reset = 1;
668  for (j = 0; j < MAX_DELAYED_PIC_COUNT; j++)
669  h->last_pocs[j] = INT_MIN;
670  break;
671  default: assert(0);
672  }
673  }
674 
675  if (!current_ref_assigned) {
676  /* Second field of complementary field pair; the first field of
677  * which is already referenced. If short referenced, it
678  * should be first entry in short_ref. If not, it must exist
679  * in long_ref; trying to put it on the short list here is an
680  * error in the encoded bit stream (ref: 7.4.3.3, NOTE 2 and 3).
681  */
682  if (h->short_ref_count && h->short_ref[0] == h->cur_pic_ptr) {
683  /* Just mark the second field valid */
685  } else if (h->cur_pic_ptr->long_ref) {
686  av_log(h->avctx, AV_LOG_ERROR, "illegal short term reference "
687  "assignment for second field "
688  "in complementary field pair "
689  "(first field is long term)\n");
690  err = AVERROR_INVALIDDATA;
691  } else {
692  pic = remove_short(h, h->cur_pic_ptr->frame_num, 0);
693  if (pic) {
694  av_log(h->avctx, AV_LOG_ERROR, "illegal short term buffer state detected\n");
695  err = AVERROR_INVALIDDATA;
696  }
697 
698  if (h->short_ref_count)
699  memmove(&h->short_ref[1], &h->short_ref[0],
700  h->short_ref_count * sizeof(Picture*));
701 
702  h->short_ref[0] = h->cur_pic_ptr;
703  h->short_ref_count++;
705  }
706  }
707 
708  if (h->long_ref_count + h->short_ref_count > FFMAX(h->sps.ref_frame_count, 1)) {
709 
710  /* We have too many reference frames, probably due to corrupted
711  * stream. Need to discard one frame. Prevents overrun of the
712  * short_ref and long_ref buffers.
713  */
715  "number of reference frames (%d+%d) exceeds max (%d; probably "
716  "corrupt input), discarding one\n",
718  err = AVERROR_INVALIDDATA;
719 
720  if (h->long_ref_count && !h->short_ref_count) {
721  for (i = 0; i < 16; ++i)
722  if (h->long_ref[i])
723  break;
724 
725  assert(i < 16);
726  remove_long(h, i, 0);
727  } else {
728  pic = h->short_ref[h->short_ref_count - 1];
729  remove_short(h, pic->frame_num, 0);
730  }
731  }
732 
733  print_short_term(h);
734  print_long_term(h);
735 
736  pps_count = 0;
737  for (i = 0; i < FF_ARRAY_ELEMS(h->pps_buffers); i++)
738  pps_count += !!h->pps_buffers[i];
739 
740  if ( err >= 0
741  && h->long_ref_count==0
742  && (h->short_ref_count<=2 || h->pps.ref_count[0] <= 1 && h->pps.ref_count[1] <= 1 && pps_count == 1)
743  && h->pps.ref_count[0]<=2 + (h->picture_structure != PICT_FRAME)
745  h->cur_pic_ptr->sync |= 1;
746  if(!h->avctx->has_b_frames)
747  h->sync = 2;
748  }
749 
750  return (h->avctx->err_recognition & AV_EF_EXPLODE) ? err : 0;
751 }
752 
754  int first_slice)
755 {
756  int i, ret;
757  MMCO mmco_temp[MAX_MMCO_COUNT], *mmco = mmco_temp;
758  int mmco_index = 0;
759 
760  if (h->nal_unit_type == NAL_IDR_SLICE) { // FIXME fields
761  skip_bits1(gb); // broken_link
762  if (get_bits1(gb)) {
763  mmco[0].opcode = MMCO_LONG;
764  mmco[0].long_arg = 0;
765  mmco_index = 1;
766  }
767  } else {
768  if (get_bits1(gb)) { // adaptive_ref_pic_marking_mode_flag
769  for (i = 0; i < MAX_MMCO_COUNT; i++) {
770  MMCOOpcode opcode = get_ue_golomb_31(gb);
771 
772  mmco[i].opcode = opcode;
773  if (opcode == MMCO_SHORT2UNUSED || opcode == MMCO_SHORT2LONG) {
774  mmco[i].short_pic_num =
775  (h->curr_pic_num - get_ue_golomb(gb) - 1) &
776  (h->max_pic_num - 1);
777 #if 0
778  if (mmco[i].short_pic_num >= h->short_ref_count ||
779  h->short_ref[ mmco[i].short_pic_num ] == NULL){
780  av_log(s->avctx, AV_LOG_ERROR,
781  "illegal short ref in memory management control "
782  "operation %d\n", mmco);
783  return -1;
784  }
785 #endif
786  }
787  if (opcode == MMCO_SHORT2LONG || opcode == MMCO_LONG2UNUSED ||
788  opcode == MMCO_LONG || opcode == MMCO_SET_MAX_LONG) {
789  unsigned int long_arg = get_ue_golomb_31(gb);
790  if (long_arg >= 32 ||
791  (long_arg >= 16 && !(opcode == MMCO_SET_MAX_LONG &&
792  long_arg == 16) &&
793  !(opcode == MMCO_LONG2UNUSED && FIELD_PICTURE(h)))) {
795  "illegal long ref in memory management control "
796  "operation %d\n", opcode);
797  return -1;
798  }
799  mmco[i].long_arg = long_arg;
800  }
801 
802  if (opcode > (unsigned) MMCO_LONG) {
804  "illegal memory management control operation %d\n",
805  opcode);
806  return -1;
807  }
808  if (opcode == MMCO_END)
809  break;
810  }
811  mmco_index = i;
812  } else {
813  if (first_slice) {
814  ret = ff_generate_sliding_window_mmcos(h, first_slice);
815  if (ret < 0 && h->avctx->err_recognition & AV_EF_EXPLODE)
816  return ret;
817  }
818  mmco_index = -1;
819  }
820  }
821 
822  if (first_slice && mmco_index != -1) {
823  memcpy(h->mmco, mmco_temp, sizeof(h->mmco));
824  h->mmco_index = mmco_index;
825  } else if (!first_slice && mmco_index >= 0 &&
826  (mmco_index != h->mmco_index ||
827  check_opcodes(h->mmco, mmco_temp, mmco_index))) {
829  "Inconsistent MMCO state between slices [%d, %d]\n",
830  mmco_index, h->mmco_index);
831  return AVERROR_INVALIDDATA;
832  }
833 
834  return 0;
835 }